The Best Home Energy Monitors of 2026 to Track Your Electricity Use Live

Not necessarily: if your utility has installed a smart meter, it may already show your usage for free in its app or online account, though often with a delay of about a day. An energy monitor adds what the utility's app doesn't: real-time readings, app history, alerts, and appliance-level data when paired with smart plugs. For whole-home readings, CT clamps go in your electrical panel; in France, a module can read the Linky smart meter's data port instead. To see what one appliance uses, a smart plug with energy monitoring is still the simplest tool.

Multiply its power in kilowatts by the hours it runs, then by your electricity rate: a 2,000 W appliance running for 1.5 hours uses 3 kWh. At an example rate of 20 cents per kWh, that's 60 cents; check the rate on your utility bill, and use the rate for those hours if you're on a time-of-use rate plan. For appliances that cycle on and off, such as refrigerators, freezers or dehumidifiers, the rating plate overstates use, so measure a full week with a smart plug and multiply by 52. Any fixed monthly charge stays the same however much you use.

Use a smart plug to find out what one appliance uses, and a CT clamp monitor to see your whole home's consumption in real time. A plug only works for appliances that plug into a standard outlet, within its maximum rating, so it can't measure a water heater, a wall oven, a cooktop or anything hardwired or on a 240 V circuit. Clamps installed around the main cables in your electrical panel capture everything, including those big loads. Many people use both: the clamps to spot when usage jumps, then plugs to track down the culprit.

Clamps that fit around cables inside your electrical panel are a job for a licensed electrician: opening the panel exposes live parts, and the incoming service cables stay live even with the main breaker off. Never open or tamper with the meter or any utility seal. Monitors that need no panel work, such as smart plugs with energy monitoring, are fine to set up yourself, as are modules that plug into France's Linky smart meter. For privacy, prefer a monitor that works locally if you don't want your usage data sent to the cloud.

Most often it's a connection problem: the transmitter is too far from your Wi-Fi router or Zigbee hub, which is common when the electrical panel or meter is in a basement, garage or hallway. Move the hub closer or add a repeater, check that each clamp is fully closed and plugged into the right input, and replace the transmitter's batteries, since dead batteries are a common cause of gaps. A module that reads France's Linky meter must also match the meter's data mode (“historique” by default, or “standard”), which the supplier can switch on request.